1. Field of the Invention
The invention relates to electronic devices and, more particularly, to electrical load management for electronic devices, such as memory systems.
2. Description of the Related Art
Memory cards are commonly used to store digital data for use with various products (e.g., electronics products). Examples of memory cards are flash cards that use Flash type or EEPROM type memory cells to store data. Flash cards have a relatively small form factor and have been used to store digital data for products such as cameras, hand-held computers, set-top boxes, hand-held or other small audio players/recorders (e.g., MP3 devices), and medical monitors. A major supplier of flash cards is SanDisk Corporation of Fremont, Calif.
FIG. 1 is a schematic diagram of a conventional voltage generation circuit 100. The conventional voltage generation circuit 100 can provide one or more generated voltages to a memory system that provides non-volatile data storage and represents, for example, a memory card (e.g., flash card). The voltage generation circuit 100 includes a charge pump circuit 102. The charge pump circuit 102 operates to boost a lower input voltage (Vin) to produce a higher output voltage (Vout). The output voltage (Vout) is coupled to a decoupling capacitor (Cd) 104. The output voltage is also coupled to a resistor divider 106. The resistor divider 106 divides the output voltage using resistors R1 and R2. A comparator 108 couples to the resistor divider 106 and to a reference voltage (Vref). The output of the comparator 108 is fed back to the charge pump circuit 102 so that the charge pump circuit 102 can regulate the output voltage such that it remains at a substantially constant voltage level.
An output voltage, such as generated by the voltage generation circuit 100, can be supplied to a memory array that provides data storage. Typically, the voltage generation circuitry and the memory array are part of a memory system (or memory device). The memory array includes a plurality of memory elements, namely, non-volatile memory elements. One of various implementations for a non-volatile memory element is a diode or antifuse type memory element. The various memory elements within the memory array can be accessed by way of bitlines and wordlines. When programming a memory element, a voltage is applied across the memory element to invoke a physical characteristic change in the memory element. As an example, when the memory element corresponds to a diode or antifuse type device, the programming of the memory element is referred to as “popping” or “blowing” the diode or antifuse.
Electronic devices, such as memory devices, are sometimes required to operate in compliance with a specification regarding its performance. One criterion of a specification can pertain to current consumption. In the case of memory devices, at least some memory arrays have a current dependency that depends on temperature. Still further, some memory arrays have a current consumption that depends on the particular data being stored in the memory array.
Conventionally, to ensure that current consumption of a memory device does not exceed a specification's criterion, performance of the memory device is limited in certain situations. For example, one high current consuming operation of a memory device is writing (i.e., programming) of its memory array. When writing to the memory array, temperature and data dependencies can significantly impact the current consumption. One conventional approach is to restrict the number of memory cells in the memory array that are able to be concurrently written (i.e., write bandwidth is restricted) whenever the temperature is elevated. Unfortunately, however, conventional approaches do not take into consideration data dependency. As a result, the performance of the memory device would often be undesirably limited beyond what would be required to satisfy a specification or other requirement.